Steve Kline 06 NOV 1998
Alan Munter 08 JULY 1999, converted to Java
APPROVED FOR DISTRIBUTION
Calculates the form factor, P(q), for a monodisperse spherical particle with uniform scattering length density. The form factor is normalized by the particle volume as described below.
Resolution smeared version is also provided.
Input Variables (default values):
|3||Incoherent Background (cm-1)||0.0|
The function calculated is:
The returned value is scaled to units of [cm-1]
Scattering contrast (Dr) = SLD (core) - SLD (solvent)
Parameter (scale) and Parameter (contrast) are both multiplicative factors in the model and are perfectly correlated. One or both of these parameters must be held fixed during model fitting.
If the scale factor Parameter is set equal to the particle volume fraction, phi, then the returned value is the scattered intensity per unit volume, I(q) = phi*P(q). However, no interparticle interference effects are included in this calculation.
Guinier, A. and G. Fournet, "Small-Angle Scattering of X-Rays", John Wiley and Sons, New York, (1955).
This example dataset is produced by calculating the Sphere using 128 data points, qmin = 0.001 Å-1, qmax = 0.3 (Å-1) and the above default parameter values.